1. Field
This invention concerns an ultra efficient vehicle, particularly a three-wheeled electric vehicle suitable for transporting one or two occupants.
2. General Discussion of the Background
There has been increasing demand in recent years for ultra efficient vehicles that carry a lesser energy and environmental footprint than traditional automobiles. Increasing adoption of hybrid vehicles featuring increased fuel efficiency is an example of this trend. Although there is a latent market demand for additional efficiency gains brought by adopting more efficient power systems, such as a battery electric drive, or more energy efficient form factors, such as two or three-wheeled vehicles, with or without a narrow body, most consumers have not chosen such offerings, as they have lacked some or all of the mass market vehicle consumer requirements: familiar feel and controls, ability to operate on all roads, capacity for a second passenger and a minimum level of reliability and perceived safety.
Examples in the prior art include narrow body vehicles proposed for increasing transportation efficiency by carrying one or more people in tandem seating. Such vehicles have three or more wheels to keep them upright when stopped. U.S. Pat. No. 4,484,648, U.S. Pat. No. 4,283,074 and U.S. Pat. No. 6,328,121 disclose narrow vehicles that utilize tilting mechanisms or ballast to provide stability when turning. Although these vehicles have significant aerodynamic and maneuverability benefits due to their small stature, their ultra-narrow form factors lead to an appearance of lack of stability. U.S. Pat. No. 5,806,622 and U.S. Pat. No. 5,960,901 disclose narrow three-wheeled vehicles designed to carry one passenger, driven from the rear wheel. The inability to carry a second passenger and rear-drive traction concerns limit the widespread adoption of such vehicles. U.S. Pat. No. 6,328,121 teaches of the importance of a high rollover threshold for ultra narrow automobiles and the importance of low center of gravity in establishing a high rollover threshold.
All of the prior art vehicles suffer from an appearance of instability or a lack of familiar feel, safety or comfort such that none has been widely adopted.